St. Augustine grass is the #1 turf choice for Florida homeowners and HOAs. Nearly 70 percent of all St. Augustine lawns in Florida are of the Floratam variety. If you’re a South Florida homeowner struggling with yellow streaks or dying patches in your lawn, it could be the viral disease known as Sugarcane Mosaic Virus (SCMV).
This virus has been causing significant damage to lawns across the South Florida region, particularly in Palm Beach County. Left unchecked, SCMV can lead to Lethal Viral Necrosis (LVN) in Floratam St. Augustine lawns, completely killing them within three years.
A Brief History of SCMV in Florida
SCMV was first identified in sugarcane fields, but it didn’t stay confined there. By the 1960s, the virus had begun infecting turfgrass, particularly in sugarcane-producing areas like rural Palm Beach County. At the time, the spread was relatively limited, thanks to the development of resistant grass varieties.
Fast-forward to 2014, and the virus reemerged in Palm Beach County lawns with devastating effects. Researchers soon confirmed that SCMV could lead to LVN—a deadly condition unique to Floratam St. Augustine. Since then, SCMV has spread throughout South Florida, threatening the lush, green lawns homeowners cherish.
Understanding Sugarcane Mosaic Virus and Lethal Viral Necrosis
SCMV is a viral disease that infects various types of grass, including St. Augustine, zoysia, and bermudagrass. While most grass types experience only mild symptoms, Floratam St. Augustine is particularly vulnerable, often progressing to LVN.
Symptoms to Watch For
- Early Signs: Yellow streaks or mosaic patterns on green grass blades.
- Progression: Brown patches develop as infected grass dies off.
- Advanced Stage: Complete lawn dieback within three years, often mistaken for fungal diseases or pest damage.
How LVN Differs from SCMV
Not every lawn infected with SCMV will develop LVN. For non-Floratam varieties, symptoms may remain mild and manageable. In Floratam lawns, however, SCMV almost always progresses to LVN, causing inevitable turf death.
How SCMV and LVN Spread
Understanding how these diseases spread is key to prevention. SCMV and LVN are primarily transmitted through:
- Mechanical Means: Mowers, trimmers, and other tools transfer infected grass sap from one lawn to another.
- Infected Sod: Sod with mild or unnoticed symptoms can bring the virus to a new location.
- Wet Grass: Mowing wet lawns increases the likelihood of spreading the virus through exposed grass blades.
Unlike fungal diseases, SCMV does not spread through soil or air. It’s also not a threat to pets, wildlife, or humans.
Preventing SCMV in Your Lawn
There’s no cure for SCMV or LVN, making prevention your best defense. Here are some proven strategies:
1. Choose Resistant Grass Varieties
If you’re considering resodding, skip Floratam and opt for resistant varieties like:
- Palmetto® St. Augustine: Known for its resistance to LVN and genetic stability.
- CitraBlue® St. Augustine: A newer option from the University of Florida with promising results.
- EMPIRE® Zoysia: A durable and chinch bug-resistant alternative for Florida lawns.
2. Practice Proper Sanitation
Sanitize equipment between uses to avoid transferring infected sap. Use solutions like:
- Diluted bleach (be cautious of corrosion on metal tools).
- Alcohol-based cleaners.
- Commercial disinfectants like Virkon S or GreenShield.
3. Mow Smart
- Avoid mowing wet grass.
- Mow healthy areas before tackling suspected infected patches.
- Clean equipment thoroughly after use.
4. Inspect Sod Before Purchase
Only buy sod from reputable suppliers and avoid sod from areas with known SCMV outbreaks.
What to Do If Your Lawn Is Infected
If you suspect SCMV or LVN, here’s what you can do:
Confirm the Diagnosis
Send a grass sample to your local UF/IFAS Extension office. This is the only way to accurately diagnose SCMV or LVN.
If you’d like to get in touch with the UF/IFAS Extension office, you can find a list of the Palm Beach County horticultural contacts here. For all other Florida counties, click here.
Replace Wisely
If LVN is confirmed, your Floratam lawn will need to be replaced with a resistant variety. Follow these steps for successful resodding:
- Remove Old Grass: Strip the infected grass completely with a sod cutter, shovel or tiller.
- Test Your Soil: Conduct a soil analysis to identify nutrient needs.
- Install New Sod: Choose a resistant grass variety, and follow proper installation practices.
- Optimize Irrigation: Perform an irrigation audit (wet check) to ensure even watering.
Choosing the Right Replacement Grass
Reinstalling Floratam is not an option—it will likely reinfect and die again within months. Consider these warm-season grass alternatives:
- Palmetto® St. Augustine: Proven to survive and thrive after LVN outbreaks.
- CitraBlue® St. Augustine: An excellent choice for South Florida lawns, though still under evaluation.
- EMPIRE® Zoysia: A robust, chinch bug-resistant grass that thrives in Florida’s climate.
Each of these options offers a fresh start for your lawn, with better resistance to diseases and pests.
FAQs About SCMV and LVN
Q: How long does it take for LVN to kill a lawn?
A: Typically, within three years. Infected patches expand over time, leading to complete lawn failure.
Q: Can LVN spread to my neighbor’s lawn?
A: Yes, if infected grass sap is transferred via mowers, trimmers, or sod. Sanitation is critical to prevent spread.
Q: How can I tell if it’s LVN or something else?
A: Symptoms like yellow streaks and dieback are common with LVN. Submit a sample for diagnosis to confirm.
The Bottom Line
Sugarcane Mosaic Virus and Lethal Viral Necrosis are serious threats to South Florida lawns, but with proper prevention and smart replacement choices, you can protect your yard. At Floridist, we specialize in providing high-quality sod installation services.
Ready to transform your lawn? Contact us today to learn more about our eco-friendly, science-backed approach to lawn care.